Shares of Tesla sank as much as 4% in trading Wednesday as the flurry of news surrounding ElonMusk’s plan to take his electric car maker private continued.

Fox Business reported Wednesday that the US' top equities regulator, the Securities and Exchange Commission, had issues subpoenas to Tesla regarding its privatization plans and Musk's "funding secured" tweet. Reporter Charles Gasparino said the investigation — which was first reported on by the Wall Street Journal last week and confirmed by Bloomberg — had reached "formal" stages.

Tesla initially skyrocketed to a new record high of $389.57 shortly after the announcement last week, but has since given up all of its gains and is now trading around $333 — 26% below the $420 price laid out by Musk.